The man who broke records by winning 74 games and $2.5 million on 'Jeopardy' shares how to remember obscure facts

$1,600 if you can tell us who took office as the 19th president of the US in 1877.

Don't feel bad — we had to look it up, too.

But for Ken Jennings, the president's name — Rutherford B. Hayes — was easy to produce. It was June, 2004 and the first of 74 "Jeopardy" games Jennings would go on to win.

It wasn't as though Jennings was especially interested in or knowledgeable about US presidential history. But he'd found a way to make memorizing obscure facts a little easier using a strategy he calls "links in a chain."

Here's how Jennings explained the technique.

He started with the president's name: Hayes. That reminded him of the song "Purple Haze," which reminded him of someone playing on a trombone. Then he thought of the play "76 Trombones," which led him to remember that Hayes was president in the 1870s.

"It's just like a pulling a wallet chain out of your pocket; you're sort of reeling it in and finally the wallet comes out, but you had to go through a few steps to get there," he told Business Insider.

The "links in a chain" technique points to an overall principle Jennings learned while preparing for "Jeopardy": Information is easier to remember when you can link it to something you already know.

Today, Jennings is a freelance writer; he's written several books for kids and adults and is currently finishing up another. He recently partnered with employee-learning platform Bridge by Instructure to create an online course about memory skills.

Jennings also recommended telling yourself a story about the obscure fact and an idea you're already familiar with.

Here's another presidential example: If you want to remember that John Quincy Adams was elected in 1824, you might tell yourself a story about the television character "Quincy" who worked a 24-hour shift.

The idea is to have fun and get a little weird — unless you're being interviewed for an article, you don't have to tell anyone what your personal links in a chain are. As long as they help you remember the information, they work.